1. Field of the Invention
The present invention relates to a vehicle-mounted knob switch device called, e.g., a stalk switch, and more particularly to a vehicle-mounted knob switch device provided with a plurality of rotatable control knobs.
2. Description of the Related Art
Generally, a vehicle-mounted knob switch device called a stalk switch is installed near a steering column of a vehicle for controlling operations of wipers, headlights, turn signals, and so on.
One example of such a conventional vehicle-mounted knob switch device will be described below by referring to an automotive headlight flashing device disclosed in Japanese Utility Model Application No. 54-181037 (Japanese Unexamined Utility Model Publication No. 56-98636) laid open in the form of a microfilm.
In this example of the vehicle-mounted knob switch device, as shown in FIG. 7, a grip portion 2, an annular control knob 16, a retaining bottom 2.sub.1 of the grip portion 2, a cylindrical control knob 6, and a retaining plate 9 of the cylindrical control knob 6 are successively attached over an end peripheral surface of a control lever (stalk) 1 in the order named. A push button type control knob 7 is attached to the foremost end of the control lever 1.
In the grip portion 2, a base plate 14, onto which a sensitivity adjusting element 15 is mounted, is fixed in opposed relation to one end face of the annular control knob 16. A slider (not shown) contacting the sensitivity adjusting element 15 is provided on an end face of the base plate 14. Sensitivity of an external illuminance detecting means (not shown) can be adjusted by rotating the annular control knob 16 about the control lever 1 as an axis. A clicking mechanism made up of a ball 17 and a spring 18 is disposed between the other end face of the annular control knob 16 and the retaining bottom 2.sub.1 of the grip portion 2 so that a click stop feeling is given in the operation of rotating the annular control knob 16.
Further, in a space of the grip portion 2 adjacent the retaining bottom 2.sub.1, there is fixed a base plate 8 onto which stationary contacts (not shown) of rotary manual flashing switches are mounted, and which is positioned in opposed relation to one end face of a bottom plate of the cylindrical control knob 6. A slider (not shown) contacting the stationary contacts (not shown) is provided on the one end face of the bottom plate. By rotating the cylindrical control knob 6 about the control lever 1 as an axis, on/off control of headlights and sidelights (not shown) can be performed. A clicking mechanism made up of a ball 10 and a spring 11 is disposed between the bottom plate of the cylindrical control knob 6 and the retaining plate 9 so that the cylindrical control knob 6 is clicked in each of operational positions.
The push button type control knob 7 is attached in such a manner as to be able to move back and forth in the longitudinal direction of the control lever 1 for turning on/off a passing switch 5.
Meanwhile, a demand for smaller size and higher functions of such a vehicle-mounted knob switch device has been increased with the increased variety and the advanced functions of electric components mounted in a vehicle.
With the conventional vehicle-mounted knob switch device, however, the following drawbacks are encountered. Because the cylindrical control knob 6, the annular control knob 16, the base plates 8, 14 respectively cooperating with the control knobs 6, 16, and the grip portion 2 with the retaining bottom 2.sub.1 and the retaining plate 9 for holding the control knobs 6, 16 are attached over the outer peripheral surface of the control lever 1, an extra space for accommodating other functional parts hardly exist forward-of the position at which the grip portion 2 is fixed to the control lever 1, and a difficulty arises in enhancing functions of the vehicle-mounted knob switch device. Further, because the cylindrical control knob 6 and the annular control knob 16 are arranged through the grip portion 2 with the retaining bottom 2.sub.1, it is also difficult to reduce the overall length of the vehicle-mounted knob switch device and to downsize the vehicle-mounted knob switch device having advanced functions.